European Publication No. 83449 A discloses a running shoe comprising a sole made of one piece of resilient material, where the rear portion of the heel is inclined and the heel includes a groove. As the heel is primarily supported by the circumference of the sole it cannot absorb all shocks opposite the correct position on the heel bone of the user.
FR-PS No. 2402425 discloses furthermore a shoe sole where the heel is provided with a knob. The knob provides no shock-absorption, and the heel per se is not a resilient portion.